If a business intelligence (BI) vendor tells you that its products are integrated with Hadoop, you should ask a lot of questions.

The hype around Hadoop has pushed many BI vendors to declare their support for the big data technology without explaining exactly what that means, Forrester analyst Boris Evelson warned in a recent blog post.

"Hadoop is not a single entity. It's a conglomeration of multiple projects, each addressing a certain niche within the Hadoop ecosystem, such as data access, data integration, DBMS, system management, reporting, analytics, data exploration and much, much more," he wrote.

If you're considering a BI tool for Hadoop environments, you need to know whether the tool works with the community version of Hadoop and with commercial versions sold by vendors such as Cloudera and Hortonworks, Evelson said.

It's also important to find out which specific components of Hadoop the BI tool integrates with. Hadoop technologies include Hive, Hbase, Pig and Sqoop.

"You really need to peel a few layers of the onion" to confirm whether any given BI tool can really work with Hadoop, he wrote.

This version of this story was originally published in Computerworld's print edition. It was adapted from an article that appeared earlier on Computerworld.com.